中文摘要：

基于岩石三轴循环加卸载蠕变试验,对试样的蠕变应变进行有效的黏弹塑性应变分离,根据试样的弹性蠕变特性和塑性蠕变特性分别建立相应的蠕变模型,继而得到岩石的黏弹塑性蠕变模型,该模型能较好地描述试样的衰减和稳态蠕变特性。为了能够较好地描述岩石加速蠕变特性,在塑性蠕变模型中引入损伤因素,建立相应的弹塑性损伤蠕变模型,对该模型参数进行敏感性分析,同时给出模型参数确定方法。所建模型黏弹塑性概念清晰,模型参数较少。对煤进行三轴循环加卸载蠕变试验,分析蠕变试验中煤样的弹塑性应变特性以及试样的稳态蠕变速率演化规律,用该黏弹塑性蠕变模型对煤样的三轴压缩蠕变试验结果进行拟合,结果表明,该模型能很好地描述循环加卸载路径下试样的弹塑性加载和弹性卸载蠕变特性。

英文摘要：

The creep strain from the creep tests under triaxial cyclic loading was separated into the viscoelastic and the viscoplastic strain and the rheological models were established accordingly to describe the variation of creep in the attenuation and steady stages. To describe the accelerated creep stage,a damage factor was introduced into the viscoplastic rheological model. As a result,a modified viscos-elastic-plastic creep model was established. The sensitivity of parameters of the model was analyzed. The creep experiment under triaxial cyclic loading on coal with various deviatoric stress levels was carried out and the elastic and plastic strains of coal were analyzed separately. Comparisons between the results obtained from creep model and creep tests showed that the proposed model described the overall rheological deformation of coal under cycle unloading path.